This invention relates to magazines for guns. More specifically it relates to large capacity drum magazines which feed cartridges to an automatic gun.
Drum magazines are well known in the art. See for example, U.S. Pat. No. 2,131,412 to Ostman; U.S. Pat. No. 4,138,923 to Brosseau; U.S. Pat. No. 4,384,508 to Sullivan; and U.S. Pat. No. 4,487,103 to Atchisson. The principal advantage of drum magazines over the more conventional box or column magazines is their greater capacity, carrying two to four times the number of cartridges of a box magazine, with correspondingly more firepower. However, such drum magazines are seldom used because they require a special gun.
Rifles are still the predominant infantry weapon today. Modern automatic rifles have two important roles. They must fire accurate single shots, which they do very well, and then by means of a selector button, they must fire fully automatic like a machine gun. The intended purpose of this second role is to eliminate the need for a secondary automatic support weapon by making the rifle an all purpose weapon. In practice, however, the rifle makes a poor machine gun. Its most obvious flaw is its small magazine, usually thirty shots. In a situation that requires full automatic fire, each magazine is emptied so quickly that the soldier must spend more time changing magazines than firing. This "down time" limits the rifle's effect and increases the soldier's vulnerability in combat.
A large capacity drum magazine for the rifle would overcome this problem by increasing the firepower of the rifle. However, existing drum magazine technology is not compatible with existing rifle technology. A gun magazine serves as both an ammunition container and as a feed device. It is, of course, an essential assembly for the gun, but unlike other assemblies within the gun, which are mechanically linked together so that their functions are coordinated, the magazine is a detachable and separate unit. The magazine's drive mechanism, without assist from the gun, must be fast enough to keep up with the gun cycle. In order to provide a large capacity magazine for automatic rifles, such as the M-16, it is necessary to move the mass of cartridges the required distance in the same time as in small capacity magazines originally designed for the gun. However, a larger weight of cartridges requires a larger force to accelerate them, and the force required to move 100 cartridges in a standard magazine design used with an M-16 would place so much force on the cartridge in the feed position that it would impede or jam the weapon mechanism.
Unlike other drum magazines, the present invention, with 100 cartridge capacity, will advance each cartridge into the feed position just as fast and with no greater binding force than for a conventional 30 cartridge magazine. Because of this and the geometry of its construction, the magazine can be used on almost any modern combat rifle without modification to the gun. It does not preclude the use of standard 30 shot magazines, so the two types can be used interchangeably.
Firepower is not always required or desirable, but when it is, the combined limit of existing rifle and magazine technology offers no better solution than a special support weapon or a bigger army. The present invention offers an entirely different solution. When needed, it triples the immediate firepower of every rifleman and reduces his vulnerability in combat.